As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: AFTER TAKE OFF LOW HYDRAULIC B PRESSURE LIGHT CAME ON. PERFORMED TROUBLESHOOTING IN ACCORDANCE WITH FIM 27-21-00-810-814. CONFIRMED INTERMITTENT FAULT. CLEANED FLIGHT CONTROL B PRESSURE SWITCH AND PLUG IN ACCORDANCE WITH AMM 20-60-02.